Goods are stored and shipped throughout the world in relatively uniform size loads that rest on either pallets or thin plates of pasteboard or other durable material known as slip sheets. Slip sheets provide cost, weight, size and other advantages as compared to pallets but are not as stiff as pallets and must therefore be supported with contact over a larger portion of their undersides than pallets. Accordingly, while pallets can be lifted and transported by contact between relatively narrow regions of the pallet understructure and forks, such as conventional lift truck forks, much wider structures must be used to support slip sheets bearing loads. Transfer of loads resting on slip sheets therefore conventionally occurs by sliding the slip sheet and load between two locations by either pushing the slip sheet and load or pulling the slip sheet by grasping an edge of the slip sheet. There are numerous drawbacks associated with these activities.
As a result, it is desirable to provide improved structures and means for transferring loads carried on slip sheets on to and off of roller conveyor systems.
Furthermore, it is desirable to provide methods and apparatus for providing safety features for operating the roller conveyor systems.